“... the Greek Dark Age began with the Dorian Invasion...”
Maybe it wasn’t really ‘dark’....Just “gray”....Maybe you can picture it................
It’s a modern invention, constructed due to the pseudochronology of Egypt.
https://freerepublic.com/focus/f-news/1774343/posts?page=35#35
All I can picture is those severe, disciplined Dorians sitting around the campfires. Oh, and subjugating the native Achaeans in Sparta.